Spark-plug electrode



B. ROSENBERG. SPARK PLUG ELECTRODE. APP'LICATION FILED FEB. 27. I918- Patented Aug. 19, 1919.

INVENTOR J5. Roaen 567:9

' I WITNESSES Q Mlzg BENJAMIN ROSENBERG, 0F BROOKLYN, NEW YORK.

SPARK-PLUG ELECTRODE.

Specification of Letters Patent.

Patented Aug. 19, 1919.

Application filed February 27, 1918. Serial No. 219,470.

To all whom it may concern Be it known that I, BENJAMIN ROSEN- BER-G, a citizen of the United States, and a resident of the city of New York, borough of Brooklyn, in the county of Kings and State of New York, have invented a new and Improved Spark-Plug Electrode, of which the 1following is a full, clear, and exact descrip- This invention relates to spark plugs and has to deal more particularly with the construction of the central electrode.

The invention has for its general objects to improve the design of electrodes so that there will always be maintained a clean sparking surface, this being obtained by the electrode embodying in its construction freely movable bodies, such as balls, which are agitated by the vibration of the engine and thereby have a cleaning effect on the electrode.

A more specific object of the invention is the provision of an electrode which has its inner end formed into an open-work hollow structure, such, for instance, as a helical coil, and in the hollow of this coil are arranged freely movable elements, such as metallic balls, which operate to provide cleaned surfaces between which and the shell electrode the sparks may jump.

With such objects in view, and others which will appear as the description proceeds, the invention comprises various novel features of construction and arrangement of parts which will be. set forth with particularity in the following description and claims appended hereto.

In the accompanying drawing, wh ch illustrates one embodiment of the lnvention and wherein similar characters of reference indicate corresponding parts in all the views,

Figure 1 1s a central vertical section of the spark plug;

bushing, 3 the clamping nut, 4 the central electro e, and 5 the shell electrode.

The central electrode 4: has a straight stem portion a and a helical coil portion b. The straight portion a extends through the bore of the bushing and the helical portion extends downwardly through and out of the shell 1, so that it will be in cooperative relation with the electrode 5 to form a spark gap therewith. Withinthe helical portion 6 are a plurality of freely movable bodies,

such as balls 6, which move about under the vibration of the engine, whereby the rubbing action will maintain clean surfaces for insuring proper sparking. The balls are retained in the coil by the lower end 7 being bent inwardly, as shown in Fig. 3.

If desired, the rod or wire from which the electrode is made can be formed with a re duced portion 8, as shown in Fig. 4, which reduced portion is shaped into the helical coil. Thus the stem portion can be made as heavy as desired for mechanical strength.

From the'foregoing description taken in connection with the accompanying drawing, the advantages of the construction and method of operation will be readily understoodby those skilled in the art to which the invention appertain s, and while I have described the principle of operation, together with the device which I now consider to be the best embodiment thereof, I desire to have it understood that the device shown is merel illustrative and that such changes may e made when desired as fall within the scope of the appended claims.

Having thus described my invention, I claim as new and desire to secure by Letters Patent:

1. A central electrode for a spark plug comprising a hollow open metallic body and a plurality of loose bodily movable elements therein.

2. An electrode for a spark plug comprising a helically coiled member, and a plu rality of freely movable bodies therein.

3. An electrode for a spark plug having a straight shank and a helically coiled sparking extremity, and balls contained within and freely movable in the coil.

4 A spark plug comprising a shell, an

electrode thereon, a bushing in the shell, and electrode thereon, a. bushing in the shell, an electrode supported by the bushing and and an electrode supported by the bushing formed with a, helical portion cooperating and formed with a helical portion cooperat- 10 With the first-mentioned electrode, and freely ing with the first-mentioned electrode, and 5 movable cleaning means within the said freely movable balls contained in the said helical portion. helical portion.

5. A spark plug comprising a shell, an BENJAMIN ROSENBERG. 

